The thing/problem im seeing with people bringing up euro oil spec or whatever other oil specs, is that it seems you guys are merging two terms or outcomes into one.
Just because an oil can reduce deposit build up, does not mean they can remove deposits. These are two different standards. What valvoline restore and protect is claiming is that for the first time, this oil can market that it removes deposits.
If you start an engine, no matter how good the fuel and oil is, you take it apart and there will be deposits forming all over the interior of the engine. Just like if you were to take a gun and shoot it, there will be residue.
What most engine oils are claiming is they can reduce this deposit formation, sometimes so low the engines will be out of service before the deposits cause any issues on their own. Just as a made up number or example, Full synthetic oils might only add 1 percent of deposits a year vs 3 or 5 for conventional. Or something like that.
Valvoline is claiming restore and protect is the first oil to go into the negative number territory, hence "cleaner at 300k miles than at 100k miles".
The question I have is how true is the claim that they are the first oil to be able to reliably market that claim?
As far as high ester oils, valvoline's own patents claim that at around 60 percent ester in the oil, you begin to show this cleaning effect. And I guess the limiting factor is that if you have too much ester, the rubber seals can be deteriorated.
So which other oils stumbled upon that effect, if any, before valvoline with the premium blue restore?
Also, according to analysis, restore and protect is not using ester at high levels like their patent mentions, instead they are using a molecule in the additive package that targets specifically the deposits found in the rings. So again, are there any other oils that are openly claiming they have additives targeting piston ring deposits? And remember, not just reduction of formation of piston ring deposits over time, but actual removal of deposits that are already there.
Like I said, I'm sure some oils that are high in ester or whatever else, might have shown some anecdotal cleaning results. But did the manufacturer themselves ever back that up or claim they could get 100% deposits within 4 oil changes or something like that? Did they ever actually give you a standard you could hold them to in terms of cleaning potential? Has anyone else done that yet?
And finally back to the original point I was making, while some oils or oil specs claim to reduce valve deposit "formation", are any of them claiming valve deposit "cleaning"? Not just reduced formation, actual reversal of those deposits already baked on there? It seems the rep for valvoline doesn't know if it will however from the statement their is a strong possibility that it would reduce deposits if it got wet enough with this oil. However how wet it actually gets probably varies between cars. And thus they can only talk about the effects of the oil on actually submerged/basted parts on the inside. I would highly doubt it would add deposits to the valves, let alone at a rate exceeding whatever euro spec, etc, oil specs that claim to reduce formations.